hints & tips please! replacing wheel arches body work

[MarkSanne]

As many of you know and/or experience themselves: the rear wheel arches on our beloved cars are a weak point. On my VR2 it is probably as bad as one has seen it now. The fact that the previous owner didn't use any protection yet rolled the arch-lip upwards probably didn't help things either.

I've asked around at body repair shops. Replacing the rear arches + spray painting will set me back around 1200 euro (1000-1100 GBP). It's nothing extreme, but I'm extremely worried those companies won't go to extremes to prevent new rust starting to build up again. This feeling is supported by a few examples of repaired arch panels that started to rust through after 6-12 months. So 'mr. paranonia' that I am, I'll need to go at it myself. My experience in metal bodywork repair is limited and something like cutting out the old wheel arch panels and replacing them with new ones is certainly no small or simple task.

40699407004069840701

Anyway: a couple of months ago I bought a set of wheel arch body panel replacement panels. The plan was to go at it in the winter. Bad idea, as I need the car now more than I do in the spring/summer/autumn (when I use my bike mostly to go to work)! So it'll happen in the spring/summer.

To cut the old parts out, I'll use my new Fein multimaster tool!
http://www.youtube.com/watch?v=DQaMxqZtRQM

To weld it all up, I'll use my trusted professional grade MIG welder. I'm nothing like a professional, but I think I have enough experience to get a good result on thin body panels.
But... how much should I cut out? The exact measurement of the replacement panel?

Anyone got some hints, tips & tricks to get this party started?

[chugg]

Hi Mark,

I've done a few rear arches in my time, but not on a galant/legnum tho, but its basically the same process for any car. And yes the best method is to remove the exact shape of the new panel. You can just 'overlap' for a quicker job but its regarded as a bit of a bodge, and to be honest its more of a pain blending it in when it's on.

- First off, check out what behind the area to weld, ie. cables/wires, fuel lines, petrol tank, interior trim etc anything that will be a problem with the heat of welding, and remove them. (remove wheel aswell an secure car on stands etc etc but you've prob guessed that bit!)
- Then offer up your new arch section, see how well it fits (some pattern parts aren't the best) and decide if how much of the new panel you need - often just a section is required or at least some of the top edge can be removed (looking at the pics you'll prob be able to lose an inch or two in places off the new panel). Obviously just be sure to leave enough on the new panel to extend past all of the rotten areas as you will be cutting them out! (maybe remove a bit of paint around the rotten area to be replace just to be sure how far the rot goes) Then measure and scribe (odd-leg dividers are good for this) how much of the top edge etc to cut off the new panel.
-Then trim the new panel with your fancy new Fein, or tin snips for us without that luxury!
Offer it up again, checking fitting again, keep an eye on the body/swage lines. When happy with the position, clamp it to the inner lip using mole grips/ panel clamps etc, check again for fitment, then mark/scribe round the panel onto the car.
-Scary bit now, take the Fein (or thin cutting disc in grinder) and chop out the shape of the new panel you have just marked on the car. Take your time do it carefully, and dont remove to much! Also remove the spot welds on the outer/inner lip of the arch. Drill them out with a cobalt spot weld remover. Sometimes it can be easier to remove the bulk of the metal and then move onto the lip after when you can, gring/wire brush it to reveal the spot weld locations.
- Once done, clean up the burred edge on the car body with a fairly coarse file.
- Then check out your inner arch lip, it often needs some attention too. Check out any other areas that need repair such as the lower rear quater area. Cut out and let in any fresh metal as required.
- Offer up your panel again, which no doubt will still need work to fit exactly. Get it in the correct position and scribe a little vertical centre line on the arch and body so you've got a something to line up to. Then, it's just a case of constant offering/clamping up the new section and removing it then trimming to fit.
-Right, after much offering up, trimming, swearing and frustration it's now a perfect fit, yes!? So now remove the paint on the car and panel ready for welding. Use a DA sander or flap wheel disc in ginder (dont use grinding disc or anything harsh or it'll score the panel/metal). Now your about ready to weld.
- First though, it;s time for that rust prevention you are concerned about. So paint the inner arch area. Just 2-pack (make sure it's well ventilated) and a brush will do . DONT just use regular primer, it's porous and will allow oxidisation. You can use rust a prevention product before painting if you like, all helps. Check out the Frost catalogue (google 'Frost') for an idea of products. It is also a good idead to coat the reverse of the new panel with Weld Thru Zinc Rich primer.
- Next drill some holes in the arch lip of the new panel, ready for when you need to 'Spot weld' (you will actually be plug welding if using the mig) onto the inner arch late.
- Then using the cenre line scribed earlier clamp the panel into it final position, checking all alignments a few times. Then check em again.
- When completly happy, tack the panels in pace together. Use the lowest heat setting you can get away with on the mig, and allow each weld to cool (touch cool - dont burn your digits tho!) before attempting another weld in that area. It is sooooooooooooooooo easy to distort the panel through overheating. Tack at opposite sides to help let it cool. Tacks about an inch apart ensureing a good fit at all times, sometimes needing a flat edge (flat screwdriver) to align the edges while you weld.
- Once thats done and all cooled down, then start seam welding between the tacks, filling in. Again altenating sides and allowing to fully cool before welding near the last weld. That will take bloody ageeeeeeeeeees.
- Then move on to plug weld the spot weld areas on the lip. Clamp the inner and outer lips together, and fill the holes you drilled earlier on the lip of the new panel with weld, so it penetrates with the inner lip. Last bit is to joint up the bit where it meets the sill.
- So, after that weld-and-cool-down-athon, you need to dress back the welds, using a course flap wheel disc, about (40 grit), then use a Roloc disc, moving onto a da sander to make the final blend of metals. Again, nothing harsh or it'll score the metal.
- Then depending on how good you welding is, there should be a minimal amount of filler work (as in body filler / plop) to do prior to giving it a coat of red oxide untill you get it painted.

Job Jobbed!

Hope that helps, it took me about an hour to write!

[MarkSanne]

MASSIVE thanks Gav for the time, effort and expertise you've put down! This will cetainly help. I will read your post several times so it really gets into my head :)

And ofcourse: have some rep!

[The Vee]

Excellent write up Chugg

/Mark, where did you get your new arches? Need a pair for mine.

[Beastlee]

Andy, there's a place over here that sells them, there was a thread from Meso about them. As before I'm happy to help where I can with regard to sourcing them.

[The Vee]

Cheers Lee, I'll have a dig around

[MarkSanne]

Left: http://cgi.ebay.co.uk/REPARATURBLECH-RADLAUF-MITSUBISHI-GALANT-LIMO-LINKS-/300514536794?pt=Autoteile_Zubeh%C3%B6r&hash=item45f80fed5a
Right: http://cgi.ebay.co.uk/REPARATURBLECH-RADLAUF-RECHTS-MITSUBISHI-GALANT-HINTEN-/370474697034?pt=Autoteile_Zubehör&hash=item564203414a

[The Vee]

Mark, that's great thank you

[The Vee]

Just ordered them! Can you tell me what "nur fur limo" means please!

[c0xxy]

google translate says:
only for limo

edit: and there is a warning that they come in a random colour!

[MarkSanne]

limo = saloon

[The Vee]

No probs - thanks guys

[Beastlee]

google translate says:
only for limo

edit: and there is a warning that they come in a random colour!

Ash, it's just a standard disclaimer that they may not look exactly as they do in the picture (shape and colour).

Andy, they do mention you should contact them if buying multiple items so as to only pay one delivery charge.

For anyone that's looking for parts Limo = Saloon and Kombi = Estate

[c0xxy]

i figured... was giggling to myself at the thought of a polka dot one turning up /woot

[chugg]

No probs Mark, ta for the rep. Glad I could be of some use! Hope you get on with it alright. You'll have to let us let us know how it goes.
@ Andrew, thanks :thumbsup:

[The Vee]

Lee, looks like they only charged me one delivery. Selected parts & then paid both together and looks like it automatically charged just one postal despite two parts - result!

[The Vee]

Got these delivered today. Very quick and quality looks good. Provided the fit is OK (no reason why it shouldn't be) then these are going to prove very good value for money. Feel like decent gauge steel too.